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        <h2 id="golang-的引用类型和内置类型变量"><a href="#golang-的引用类型和内置类型变量" class="headerlink" title="golang 的引用类型和内置类型变量"></a>golang 的引用类型和内置类型变量</h2><p>golang 中变量类型分为引用类型和值类型(也叫作内置类型)</p>
<h3 id="1-值类型：变量直接存储值，内存通常在栈中分配。"><a href="#1-值类型：变量直接存储值，内存通常在栈中分配。" class="headerlink" title="1.值类型：变量直接存储值，内存通常在栈中分配。"></a>1.值类型：变量直接存储值，内存通常在栈中分配。</h3><p>值类型：基本数据类型int、float、bool、string以及数组和struct</p>
<h3 id="2-引用类型：变量存储的是一个地址，这个地址存储最终的值。内存通常在-堆上分配。通过GC回收。"><a href="#2-引用类型：变量存储的是一个地址，这个地址存储最终的值。内存通常在-堆上分配。通过GC回收。" class="headerlink" title="2.引用类型：变量存储的是一个地址，这个地址存储最终的值。内存通常在 堆上分配。通过GC回收。"></a>2.引用类型：变量存储的是一个地址，这个地址存储最终的值。内存通常在 堆上分配。通过GC回收。</h3><p>引用类型：指针、slice、map、chan等都是引用类型。这类型变量需要通过make构造</p>
<h2 id="golang中函数传参只有一种方式"><a href="#golang中函数传参只有一种方式" class="headerlink" title="golang中函数传参只有一种方式"></a>golang中函数传参只有一种方式</h2><p>golang中函数传递参数，只有值传递一种，也就是实参内容按照值copy方式传递给形参。<br>当函数的形参变量类型为指针,slice,map,chan等类型时，虽然实参和形参地址不同，但是内部指向了同一个地址，所以可以达到修改指定空间数据的目的。<br>不要着急，接下来我会写一写小demo帮助大家理解。<br><a id="more"></a></p>
<h2 id="数组"><a href="#数组" class="headerlink" title="数组"></a>数组</h2><p>先把这段代码写一遍看看结果<br><figure class="highlight golang"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">//数组声明方法</span></span><br><span class="line">	<span class="keyword">var</span> bytearray [<span class="number">8</span>]<span class="keyword">byte</span> <span class="comment">//长度为8的数组</span></span><br><span class="line">	fmt.Println(bytearray)</span><br><span class="line">	<span class="keyword">var</span> pointarray [<span class="number">4</span>]*<span class="keyword">float64</span> <span class="comment">//指针数组</span></span><br><span class="line">	fmt.Println(pointarray)</span><br><span class="line">	<span class="keyword">var</span> mularray [<span class="number">3</span>][<span class="number">5</span>]<span class="keyword">int</span></span><br><span class="line">	fmt.Println(mularray)</span><br><span class="line">	fmt.Printf(<span class="string">" pointarray len is %v\n"</span>, <span class="built_in">len</span>(pointarray))</span><br><span class="line">	<span class="comment">//数组遍历</span></span><br><span class="line">	<span class="keyword">for</span> i := <span class="number">0</span>; i &lt; <span class="built_in">len</span>(pointarray); i++ &#123;</span><br><span class="line">		fmt.Println(<span class="string">"Element"</span>, i, <span class="string">"of array is"</span>, pointarray[i])</span><br><span class="line">	&#125;</span><br><span class="line"></span><br><span class="line">	<span class="comment">//采用range遍历</span></span><br><span class="line">	<span class="keyword">for</span> i, v := <span class="keyword">range</span> pointarray &#123;</span><br><span class="line">		fmt.Println(<span class="string">"Array element ["</span>, i, <span class="string">"]="</span>, v)</span><br><span class="line">	&#125;</span><br></pre></td></tr></table></figure></p>
<p>上边提供了数组的声明方式 var 数组名 [数组长度] 元素类型，<br>同时给出了两种数组遍历方式：<br>1 len(数组名) 可以获取数组大小，然后遍历<br>2 采用range遍历，第一个返回值是索引，第二个返回值是对应的内容<br>int 类型数组初始值为0，指针类型数组初始值为nil<br>结果如下:<br><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line">[0 0 0 0 0 0 0 0]</span><br><span class="line">[&lt;nil&gt; &lt;nil&gt; &lt;nil&gt; &lt;nil&gt;]</span><br><span class="line">[[0 0 0 0 0] [0 0 0 0 0] [0 0 0 0 0]]</span><br><span class="line"> pointarray len is 4</span><br><span class="line">Element 0 of array is &lt;nil&gt;</span><br><span class="line">Element 1 of array is &lt;nil&gt;</span><br><span class="line">Element 2 of array is &lt;nil&gt;</span><br><span class="line">Element 3 of array is &lt;nil&gt;</span><br><span class="line">Array element [ 0 ]= &lt;nil&gt;</span><br><span class="line">Array element [ 1 ]= &lt;nil&gt;</span><br><span class="line">Array element [ 2 ]= &lt;nil&gt;</span><br><span class="line">Array element [ 3 ]= &lt;nil&gt;</span><br></pre></td></tr></table></figure></p>
<p>前文说过数组是值类型变量，我们写个函数，在函数内部修改形参数组的变量内容，看是否会对实参影响<br><figure class="highlight golang"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><span class="line"><span class="function"><span class="keyword">func</span> <span class="title">modify</span><span class="params">(array [5]<span class="keyword">int</span>)</span></span> &#123;</span><br><span class="line">	array[<span class="number">0</span>] = <span class="number">200</span></span><br><span class="line">    fmt.Println(<span class="string">"In modify(), array values:"</span>, array)</span><br><span class="line">&#125;</span><br><span class="line"><span class="function"><span class="keyword">func</span> <span class="title">main</span><span class="params">()</span></span>&#123;</span><br><span class="line">    array := [<span class="number">5</span>]<span class="keyword">int</span>&#123;<span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>&#125;</span><br><span class="line">	modify(array)</span><br><span class="line">	fmt.Println(<span class="string">"In main(), array values:"</span>, array)</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure></p>
<p>结果如下<br><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">In modify(), array values: [200 2 3 4 5]</span><br><span class="line">In main(), array values: [1 2 3 4 5]</span><br></pre></td></tr></table></figure></p>
<p>说明实参没有被函数修改。那么既然golang传递变量的方式都是值传递，是不是就没办法通过函数修改外部变量了呢？<br>肯定不是的，可以通过引用类型变量修改，比如指针，slice，map，chan等都可以在函数体内修改，从而影响外部实参的内容。<br>下面通过slice说明这一点</p>
<h2 id="slice切片"><a href="#slice切片" class="headerlink" title="slice切片"></a>slice切片</h2><p>先看代码<br><figure class="highlight golang"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br></pre></td><td class="code"><pre><span class="line">array := [<span class="number">5</span>]<span class="keyword">int</span>&#123;<span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>&#125;</span><br><span class="line"><span class="comment">//根据数组生成切片</span></span><br><span class="line"><span class="comment">//切片</span></span><br><span class="line">	<span class="keyword">var</span> mySlice []<span class="keyword">int</span> = array[:<span class="number">3</span>]</span><br><span class="line">	fmt.Println(<span class="string">"Elements of array"</span>)</span><br><span class="line">	<span class="keyword">for</span> _, v := <span class="keyword">range</span> array &#123;</span><br><span class="line">		fmt.Print(v, <span class="string">" "</span>)</span><br><span class="line">	&#125;</span><br><span class="line">	fmt.Println(<span class="string">"\nElements of mySlice: "</span>)</span><br><span class="line">	<span class="keyword">for</span> _, v := <span class="keyword">range</span> mySlice &#123;</span><br><span class="line">		fmt.Print(v, <span class="string">" "</span>)</span><br><span class="line">    &#125;</span><br><span class="line">    </span><br><span class="line">    <span class="comment">//直接创建元素个数为5的数组切片</span></span><br><span class="line">	mkslice := <span class="built_in">make</span>([]<span class="keyword">int</span>, <span class="number">5</span>)</span><br><span class="line">	fmt.Println(<span class="string">"\n"</span>, mkslice)</span><br><span class="line">	<span class="comment">//创建初始元素个数为5的切片，元素都为0，且预留10个元素存储空间</span></span><br><span class="line">	mkslice2 := <span class="built_in">make</span>([]<span class="keyword">int</span>, <span class="number">5</span>, <span class="number">10</span>)</span><br><span class="line">	fmt.Println(<span class="string">"\n"</span>, mkslice2)</span><br><span class="line">	mkslice3 := []<span class="keyword">int</span>&#123;<span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>&#125;</span><br><span class="line">	fmt.Println(<span class="string">"\n"</span>, mkslice3)</span><br><span class="line"></span><br><span class="line">	<span class="comment">//元素遍历</span></span><br><span class="line">	<span class="keyword">for</span> i := <span class="number">0</span>; i &lt; <span class="built_in">len</span>(mkslice3); i++ &#123;</span><br><span class="line">		fmt.Println(<span class="string">"mkslice3["</span>, i, <span class="string">"] ="</span>, mkslice3[i])</span><br><span class="line">	&#125;</span><br><span class="line"></span><br><span class="line">	<span class="comment">//range 遍历</span></span><br><span class="line">	<span class="keyword">for</span> i, v := <span class="keyword">range</span> mkslice3 &#123;</span><br><span class="line">		fmt.Println(<span class="string">"mkslice3["</span>, i, <span class="string">"] ="</span>, v)</span><br><span class="line">	&#125;</span><br></pre></td></tr></table></figure></p>
<h3 id="生成切片有三种方式"><a href="#生成切片有三种方式" class="headerlink" title="生成切片有三种方式"></a>生成切片有三种方式</h3><p>1 通过数组或者切片截取生成新的切片<br>2 通过make生成 如mkslice := make([]int, 5)<br>3 直接初始化 如mkslice3 := []int{1, 2, 3, 4, 5}<br>切片遍历和数组遍历类似，上面结果如下<br><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br></pre></td><td class="code"><pre><span class="line">Elements of array</span><br><span class="line">1 2 3 4 5</span><br><span class="line">Elements of mySlice:</span><br><span class="line">1 2 3</span><br><span class="line"></span><br><span class="line"> [0 0 0 0 0]</span><br><span class="line"></span><br><span class="line"> [0 0 0 0 0]</span><br><span class="line"></span><br><span class="line"> [1 2 3 4 5]</span><br><span class="line">mkslice3[ 0 ] = 1</span><br><span class="line">mkslice3[ 1 ] = 2</span><br><span class="line">mkslice3[ 2 ] = 3</span><br><span class="line">mkslice3[ 3 ] = 4</span><br><span class="line">mkslice3[ 4 ] = 5</span><br><span class="line">mkslice3[ 0 ] = 1</span><br><span class="line">mkslice3[ 1 ] = 2</span><br><span class="line">mkslice3[ 2 ] = 3</span><br><span class="line">mkslice3[ 3 ] = 4</span><br><span class="line">mkslice3[ 4 ] = 5</span><br></pre></td></tr></table></figure></p>
<h3 id="获取切片大小和容量"><a href="#获取切片大小和容量" class="headerlink" title="获取切片大小和容量"></a>获取切片大小和容量</h3><figure class="highlight golang"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">//获取size和capacity</span></span><br><span class="line">	mkslice4 := <span class="built_in">make</span>([]<span class="keyword">int</span>, <span class="number">5</span>, <span class="number">10</span>)</span><br><span class="line">	fmt.Println(<span class="string">"len(mkslice4):"</span>, <span class="built_in">len</span>(mkslice4))</span><br><span class="line">	fmt.Println(<span class="string">"cap(mkslice4):"</span>, <span class="built_in">cap</span>(mkslice4))</span><br></pre></td></tr></table></figure>
<p>获取大小采用len,获取实际开辟的容量用cap</p>
<h3 id="切片添加和删除"><a href="#切片添加和删除" class="headerlink" title="切片添加和删除"></a>切片添加和删除</h3><figure class="highlight golang"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">//末尾添加三个元素</span></span><br><span class="line">	mkslice4 = <span class="built_in">append</span>(mkslice4, <span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>)</span><br><span class="line">	fmt.Println(<span class="string">"mkslice4 is : "</span>, mkslice4)</span><br><span class="line"></span><br><span class="line">	mkslice4 = <span class="built_in">append</span>(mkslice4, mkslice3...)</span><br><span class="line">	fmt.Println(<span class="string">"mkslice4 is : "</span>, mkslice4)</span><br></pre></td></tr></table></figure>
<p>采用append 方式可以添加切片数据，但是要注意将append赋值给要存储结果的slice<br>append有两种用法，第一种是多个参数，第一个参数是slice，后边是要加的多个元素。<br>第二种是第一个参数为slice，第二个参数为slice展开，slice…表示把slice中元素一个个展开加入。<br>切片的删除较为麻烦，比如说删除第n个元素，就是截取n-1之前的序列和n之后的序列进行拼接。<br><figure class="highlight golang"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br></pre></td><td class="code"><pre><span class="line">   mkslice4 := <span class="built_in">make</span>([]<span class="keyword">int</span>, <span class="number">0</span>)</span><br><span class="line"></span><br><span class="line"><span class="comment">//末尾添加三个元素</span></span><br><span class="line">mkslice4 = <span class="built_in">append</span>(mkslice4, <span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>)</span><br><span class="line">fmt.Println(<span class="string">"mkslice4 is : "</span>, mkslice4)</span><br><span class="line">mkslice3 := []<span class="keyword">int</span>&#123;<span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>&#125;</span><br><span class="line">mkslice4 = <span class="built_in">append</span>(mkslice4, mkslice3...)</span><br><span class="line"></span><br><span class="line">fmt.Println(<span class="string">"mkslice4 is : "</span>, mkslice4)</span><br><span class="line">mkslice4 = <span class="built_in">append</span>(mkslice4[:<span class="number">4</span><span class="number">-1</span>], mkslice4[<span class="number">4</span>:]...)</span><br><span class="line">fmt.Println(<span class="string">"mkslice4 is : "</span>, mkslice4)</span><br></pre></td></tr></table></figure></p>
<h3 id="切片的copy"><a href="#切片的copy" class="headerlink" title="切片的copy"></a>切片的copy</h3><p>copy函数提供了切片的深层复制，而赋值操作(=)紧紧是浅拷贝。<br>看看赋值操作，我们修改slice内部元素数据，其他slice是否会受到影响<br><figure class="highlight golang"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line">   oldslice := []<span class="keyword">int</span>&#123;<span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>&#125;</span><br><span class="line">newslice := oldslice[:<span class="number">3</span>]</span><br><span class="line">newslice2 := oldslice</span><br><span class="line">fmt.Println(<span class="string">"newslice is :"</span>, newslice)</span><br><span class="line">fmt.Println(<span class="string">"newslice2 is :"</span>, newslice2)</span><br><span class="line">fmt.Printf(<span class="string">"newslice addr is : %p \n"</span>, &amp;newslice)</span><br><span class="line">fmt.Printf(<span class="string">"newslice2 addr is:  %p \n"</span>, &amp;newslice2)</span><br><span class="line">oldslice[<span class="number">0</span>] = <span class="number">1024</span></span><br><span class="line">fmt.Println(<span class="string">"newslice is :"</span>, newslice)</span><br><span class="line">fmt.Println(<span class="string">"newslice2 is :"</span>, newslice2)</span><br></pre></td></tr></table></figure></p>
<p>输出一下<br><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line">newslice is : [1 2 3]</span><br><span class="line">newslice2 is : [1 2 3 4 5]</span><br><span class="line">newslice addr is : 0xc00005a400</span><br><span class="line">newslice2 addr is:  0xc00005a420</span><br><span class="line">newslice is : [1024 2 3]</span><br><span class="line">newslice2 is : [1024 2 3 4 5]</span><br></pre></td></tr></table></figure></p>
<p>可以看到oldslice修改后，newslice和newslice2都受到影响了，即便他们地址不同。<br>为什么呢?这要追溯到slice内部实现<br><figure class="highlight golang"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">type</span> Slice <span class="keyword">struct</span> &#123;</span><br><span class="line">    ptr   unsafe.Pointer        <span class="comment">// Array pointer</span></span><br><span class="line">    <span class="built_in">len</span>   <span class="keyword">int</span>               <span class="comment">// slice length</span></span><br><span class="line">    <span class="built_in">cap</span>     <span class="keyword">int</span>               <span class="comment">// slice capacity</span></span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure></p>
<p>Slice 内部其实存放了一个指针ptr，这个ptr指向的地址就是存放数据连续空间的首地址，len表示空间当前长度，cap表示空间实际开辟了多大。<br>如下图<br><img src="1.jpg" alt="1.jpg"><br>那如何深copy元素到另一个slice呢？就是copy函数了<br><figure class="highlight golang"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br></pre></td><td class="code"><pre><span class="line">   slice1 := []<span class="keyword">int</span>&#123;<span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>&#125;</span><br><span class="line">slice2 := []<span class="keyword">int</span>&#123;<span class="number">5</span>, <span class="number">4</span>, <span class="number">3</span>&#125;</span><br><span class="line"><span class="built_in">copy</span>(slice2, slice1)</span><br><span class="line">fmt.Println(<span class="string">"after copy....."</span>)</span><br><span class="line">fmt.Println(<span class="string">"slice1: "</span>, slice1)</span><br><span class="line">fmt.Println(<span class="string">"slice2: "</span>, slice2)</span><br><span class="line">slice2[<span class="number">0</span>] = <span class="number">1024</span></span><br><span class="line">slice2[<span class="number">1</span>] = <span class="number">999</span></span><br><span class="line">slice2[<span class="number">2</span>] = <span class="number">1099</span></span><br><span class="line">fmt.Println(<span class="string">"after change element slice2..."</span>)</span><br><span class="line">fmt.Println(<span class="string">"slice1: "</span>, slice1)</span><br><span class="line">fmt.Println(<span class="string">"slice2: "</span>, slice2)</span><br><span class="line"><span class="built_in">copy</span>(slice1, slice2)</span><br><span class="line">fmt.Println(<span class="string">"after copy....."</span>)</span><br><span class="line">fmt.Println(<span class="string">"slice1: "</span>, slice1)</span><br><span class="line">fmt.Println(<span class="string">"slice2: "</span>, slice2)</span><br></pre></td></tr></table></figure></p>
<p>结果如下<br><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><span class="line">after copy.....</span><br><span class="line">slice1:  [1 2 3 4 5]</span><br><span class="line">slice2:  [1 2 3]</span><br><span class="line">after change element slice2..</span><br><span class="line">slice1:  [1 2 3 4 5]</span><br><span class="line">slice2:  [1024 999 1099]</span><br><span class="line">after copy.....</span><br><span class="line">slice1:  [1024 999 1099 4 5]</span><br><span class="line">slice2:  [1024 999 1099]</span><br></pre></td></tr></table></figure></p>
<p>可以看到copy(destslice,srcslice)，当destslice 大小&lt; srcslice时，只拷贝destslice大小的数据。<br>也就是说copy的大小取决于destslice和srcslice最小值<br>另外copy后，修改slice2元素，slice1也不会受到影响，是深copy。<br>感谢关注我的公众号<br><img src="wxgzh.jpg" alt="wxgzh.jpg"></p>

      
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              <div class="post-toc-content"><ol class="nav"><li class="nav-item nav-level-2"><a class="nav-link" href="#golang-的引用类型和内置类型变量"><span class="nav-number">1.</span> <span class="nav-text">golang 的引用类型和内置类型变量</span></a><ol class="nav-child"><li class="nav-item nav-level-3"><a class="nav-link" href="#1-值类型：变量直接存储值，内存通常在栈中分配。"><span class="nav-number">1.1.</span> <span class="nav-text">1.值类型：变量直接存储值，内存通常在栈中分配。</span></a></li><li class="nav-item nav-level-3"><a class="nav-link" href="#2-引用类型：变量存储的是一个地址，这个地址存储最终的值。内存通常在-堆上分配。通过GC回收。"><span class="nav-number">1.2.</span> <span class="nav-text">2.引用类型：变量存储的是一个地址，这个地址存储最终的值。内存通常在 堆上分配。通过GC回收。</span></a></li></ol></li><li class="nav-item nav-level-2"><a class="nav-link" href="#golang中函数传参只有一种方式"><span class="nav-number">2.</span> <span class="nav-text">golang中函数传参只有一种方式</span></a></li><li class="nav-item nav-level-2"><a class="nav-link" href="#数组"><span class="nav-number">3.</span> <span class="nav-text">数组</span></a></li><li class="nav-item nav-level-2"><a class="nav-link" href="#slice切片"><span class="nav-number">4.</span> <span class="nav-text">slice切片</span></a><ol class="nav-child"><li class="nav-item nav-level-3"><a class="nav-link" href="#生成切片有三种方式"><span class="nav-number">4.1.</span> <span class="nav-text">生成切片有三种方式</span></a></li><li class="nav-item nav-level-3"><a class="nav-link" href="#获取切片大小和容量"><span class="nav-number">4.2.</span> <span class="nav-text">获取切片大小和容量</span></a></li><li class="nav-item nav-level-3"><a class="nav-link" href="#切片添加和删除"><span class="nav-number">4.3.</span> <span class="nav-text">切片添加和删除</span></a></li><li class="nav-item nav-level-3"><a class="nav-link" href="#切片的copy"><span class="nav-number">4.4.</span> <span class="nav-text">切片的copy</span></a></li></ol></li></ol></div>
            

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